<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    我是index页面，只能手机访问
</body>
</html>
<script>
        var system = {};
      var p = navigator.platform;
      var u = navigator.userAgent;
    
      system.win = p.indexOf("Win") == 0;
      system.mac = p.indexOf("Mac") == 0;
      system.xll = (p == "X11") || (p.indexOf("Linux") == 0);
      if (system.win || system.mac || system.xll) {//如果是PC端
       // window.location.href = " demo2.html";
        if (u.indexOf('Windows Phone') > -1) {  //win手机端
          
        }else {
          window.location.href = " demo.html";
        }
      }
</script>